HYDERABAD: Hopes for two engineers and six labourers trapped in the Srisailam Left Bank Canal (SLBC) tunnel in Telangana‘s Nagarkurnool district are diminishing, as more than 48 hours of strenuous efforts to rescue the eight people have come to a standstill, with rising water levels and shifting silt making the operation riskier by the hour.
The eight people were trapped deep inside the tunnel when the tunnel roof caved in on Feb 22, while 52 others managed to come out to safety. By late Monday evening, family members of some of the trapped people were also flown in by the authorities.
State govt, which initially considered vertical drilling and digging from the top of the tunnel, above 400 metres, has now abandoned that approach. Instead, the authorities have decided to continue efforts from within the tunnel to mitigate any potential harm to rescuers. The increased water inflow and the sudden accumulation of silt have raised grave concerns about the structural integrity of the tunnel, forcing officials to reconsider their strategy.
On Monday morning, rescue teams entered the tunnel to assess the situation, only to find that the silt had increased by about one metre, to over seven metres. The influx of water continued unabated, complicating the dewatering process. Experts suspect the fresh water surge could be due to either a sudden increase in activity at the collapsed roof or the onset of a new collapse-though they have been unable to confirm this. Officials further reported that the tunnel boring machine had moved 500 metres, likely due to the rising water, and the conveyor belt used for material removal was damaged.
The rescue operation remains on hold as the authorities tread carefully, awaiting more information on how best to proceed without endangering additional lives.
The National Highways and Infrastructure Development Corporation Limited (NHIDCL) urged govt to slow down operations and proceed with utmost caution. No risks could be taken at this point, they advised, suggesting the tunnel should be observed for any further signs of collapse while the water and silt gushed in.
Australian tunnel expert Chris Cooper, too, strongly urged against using gas-cutters or any form of digging, emphasising that the area near the collapsed roof remained unstable. He advised waiting for a more thorough assessment before any further action could be taken.
“To gain a clearer picture of the terrain and soil conditions, govt has sent coordinates and maps to institutions like the National Remote Sensing Centre, National Geophysical Research Institute, and Geological Survey of India for further analysis,” a senior official said.
